Heterometal–Heterocoordination Synergy in Dual-Site Single-Atom Catalysts for Selective Nonradical Persulfate Activation

The rational design of catalysts that enable efficient and selective persulfate activation under practical conditions remains a major challenge in wastewater treatment. Herein, we report a dual-site single-atom catalyst (CoZn-SNC) featuring atomically dispersed Co and Zn stabilized within N, S-coordinated carbon frameworks. Structural analyses confirmed the isolated nature of both Co and Zn sites, while catalytic evaluations demonstrated superior performance for a wide range of organic pollutants. Remarkably, CoZn-SNC achieved complete phenol degradation within 3 min at pH 11 with a total organic carbon removal efficiency of 80.34%, outperforming monometallic counterparts. The catalyst maintained excellent activity in diverse real-water matrices and continuous-flow systems, underscoring its practical robustness. Mechanistic investigations revealed that 1O2 and O2•– dominate the degradation pathway, rather than hydroxyl or sulfate radicals. Density functional theory calculations showed that Zn coordination modulates the electronic structure of Co sites, facilitating cooperative adsorption of O2 and PMS and lowering the barrier for OOH formation, thereby promoting 1O2 generation. This work establishes a “heterometal–heterocoordination–dual-substrate synergy” strategy, providing new design principles for nonradical AOPs and advancing scalable solutions for selective and resilient wastewater treatment.